September 15, 2013

I've Been Waiting For This One...

Today on the op-ed page of the Pittsburgh Tribune-Review, we find this:

A funny thing has happened on the way to the polar ice caps melting and inundating our coastal cities. The National Snow and Ice Data Center says 1 million more square miles of ocean are covered in ice this year versus last. Which has prompted University of Wisconsin researcher Anastasios Tsonis to note that the Earth is in a cooling phase that could last for at least the next 15 years. And what do we say, class, upon learning of such news? All together now: “Throw another log on the fire, honey. It's getting cold outside.”[Bolding in original.]

Sea ice is frozen ocean water that melts each summer and then refreezes each winter. It typically reaches its smallest "extent" in September and largest in March of each year.

The data center reported Wednesday that the extent of Arctic sea ice shrank to 1.98 million square miles on Tuesday. Last year, at its smallest point, the amount of sea ice shrank to 1.32 million square miles.

That's a difference of about 2/3 of a million square miles - the braintrust said it was a "million more." Messy sloppy mistake, guys. It's embarrassing to make such a simple mistake, doncha think?

Anyway, even if they got that simplest of facts right (which they didn't), they're still misleading you with a bit of a statistical fallacy. What they're doing is called "regression toward the mean." Basically what that means is that since the previous summer (of 2012) was so bad, anything not so bad can be seen as "recovering" while in reality it's really just moving back to the average (which is already bad and getting worse). Here's the lede from the USAToday piece:

Sea ice in the Arctic will reach its annual minimum "any day now," says Mark Serreze, director of the National Snow and Ice Data Center, which tracks Arctic ice.

Although not nearly as ice-free as last September's all-time record low, the amount of Arctic sea ice in the summer of 2013 was well below average, and will likely go in the books as the sixth-smallest "extent" of Arctic sea ice on record,he says. [Emphasis added.]

In it's debunking of this story, Slate.com was even good enough to add a chart from the NSIDC to show what's happening:

I guess the braintrust didn't bother to take a look at this chart from the very same source it uses as the foundation of it's most recent warm and steamy pile of anti-science.

See that light blue line? That's this year. The dotted line is last year and the darker grey is the average. See how last year, while above last year, is still below the average? Additionally, see how it's consistently below the 1981-2010 average? See how what the climate deniers at the Trib and on Facebook are completely wrong?

The contentious part of our paper is that the climate system appears to have had another “episode” around the turn of the 21st century, coinciding with the much discussed “halt” in global warming. Whether or not such a halt has really occurred is of course controversial (it appears quite marked in the HadCRUT3 data, less so in GISTEMP); only time will tell if it’s real. Regardless, it’s important to note that we are not talking about global cooling, just a pause in warming. [Bolding in original.]